1. Field of the Invention
The present invention relates to a drive unit for an electric vehicle having a planetary reduction gearing. More specifically, the present invention relates to an in-wheel type drive unit having a motor and a planetary reduction gearing positioned on the internal circumference side of a wheel rim.
2. Background Information
Japanese Laid-Open Patent Publication No. 2002-247713 discloses one example of a conventional in-wheel drive unit in which an output shaft is rotatably supported by bearings and operatively coupled to a hub flange of a wheel rim, with a reduction planetary gear train and a motor arranged along the axis of rotation. Japanese Laid-Open Patent Publication No. 2001-032888 discloses another example of a conventional in-wheel drive unit in which an output shaft is rotatably supported by bearings and operatively coupled to a hub flange, but with a pair of reduction planetary gear sets arranged along the axis of rotation and a motor arranged around the outer circumference of the planetary reduction gear sets.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved in-wheel drive unit. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.